Multiconfigurational Dirac–Fock energy levels and radiative rates for Ni XXI

Abstract

We present accurate atomic structure calculations for the lowest 200 fine structural energy levels for oxygen-like nickel, which may be a useful ion for both astrophysical and fusion plasmas. For the calculations of energy levels and radiative rates, we have used the multiconfigurational Dirac–Fock method. Our results are compared with those obtained using other numerical methods and experiments so that their accuracy can be assessed. The transition wavelengths, oscillator strengths, and radiative rates are reported for electric dipole (E1) transitions from the ground state. We have also presented the transition probabilities and transition wavelength of some forbidden transitions. Finally, we predict new energy levels, oscillator strengths, and transition probability data, where no other theoretical or experimental results are available, which may be useful for future experimental work.